The present invention relates generally to an automatic door locking/unlocking device for an automotive vehicle for automatically locking and unlocking the vehicle door. More particularly, the invention relates to the automatic door locking/unlocking device which does not require extremely high accuracy in manufacturing each consisting element and in assembling them to form the door lock mechanism.
The automatic door locking/unlocking device generally includes an electric reversible motor for driving an actuation member to lock and unlock the vehicle door. A door lock/unlock switch can be facilitated adjacent a driver's seat for manual operation by a driver or a passenger in the front seat. The electric motor is responsive to turning on of the door lock/unlock switch to the lock or unlock the door depending upon the switch position. The automatic door lock/unlock device, in turn, permits manual door lock or unlock operation in a per se well known manner.
It will be appreciated that the door lock/unlock switch is not always required for the automatic door locking/unlocking device of the present invention. Namely, the manually operable door lock mechanism of a door beside the driver's seat can be utilized as a driving switch for driving the electric motor, in a fully automatic door lock/unlock system.
In such an automatic door lock/unlock device, a stop mechanism is provided for stopping the electric motor at a predetermined locking and unlocking position to prevent the electric motor from overrunning. In the conventional device, the stop mechanism is adapted to detect a predetermined stroke of the actuation member movement. Therefore, unless the actuation member movement stroke accurately corresponds to the door locking position and unlocking position, the conventional door locking/unlocking device may not work well. If the stop mechanism does not work accurately, it may cause damage to the electric motor.
To obtain an accurate stroke of the actuation member, it is required to manufacture with high accuracy the size and construction of consisting elements in the conventional device. Furthermore, assembling the conventional automatic door locking/unlocking device also requires high accuracy. These requirements necessarily inhibit production of the automatic door locking/unlocking device and cause a relatively high cost thereof.